Ultrasonic cleaning devices are commonly employed in the cleaning of medical instruments, especially those comprising a plurality of undercuts. In the use of an ultrasonic cleaning device, the contaminated instruments are placed in a basin of water which is then exposed to ultrasonic energy, that generates ultrasonic waves in the water. The waves produce cavitation in the water, resulting in the creation of cavitation bubbles, which ultimately collapse. As the bubbles collapse, they become convoluted on one side due to a jet of fluid that shoots through the bubble at high speed as it collapses. The jet of fluid then hits on the opposite side of the bubble, often at speeds of up to 500 m/s. The cleaning effect of the device results from the jets of fluid, which hit the contaminated instruments at these high speeds, and thereby remove impurities from the instrument surfaces.
Due to the non-homogeneous distribution of ultrasonic waves in the basin, regions of both low cavitation density and high cavitation density are created. Naturally, the regions having a high cavitation density will yield a higher cleaning efficiency than the lower cavitation density. Unfortunately, because the movement of the ultrasonic waves is not visible and the cavitation bubbles are very difficult to see, it is not possible to identify the regions having a high cavitation density, and therefore a high cleaning efficiency solely by observing the water in the cleaning basin.
One known method of testing the efficiency of ultrasonic cleaning devices involves the immersion of thin, conventional aluminum foil into the water basin. As cavitation occurs, small holes are created in the foil by the cavitation bubbles, whereby it is possible to identify the density of areas of cavitation. The disadvantage of this method is that it does not provide an objective and reproducible test parameter, for the user to reliably judge the efficiency of the ultrasonic device.
It is therefore desirable to provide a device and method that enables the reliable and reproducible testing of the cleaning efficiency of an ultrasonic cleaning device. As described in detail herein, the present invention provides such a device and method.